Add Intergas InComfort Lan2RF Gateway (#9401)

* Initial commit - markdown & image

* bugfix: Please do not change

* fix typo string for integer

* ✏️ Tweak

After this we will merge it

* ✏️ Change requirements

source/_components/incomfort.markdown

@@ -0,0 +1,55 @@
+---
+layout: page
+title: "Intergas InComfort"
+description: "Instructions on how to integrate an Intergas Lan2RF gateway with Home Assistant."
+date: 2019-03-03 16:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: incomfort.png
+ha_category:
+  - Water heater
+ha_release: 0.93
+ha_iot_class: Local Polling
+---
+
+The `incomfort` integration links Home Assistant with your Intergas Lan2RF gateway for controlling water_heater devices (the hub does not have to be in the same network as HA).
+
+The **Water Heater** device will report back the `state` and `temperature`. Other properties are available via the device's attributes.
+
+In the future, other entities will be added to this integration (e.g. a **Sensor** for CV pressure, and a **Climate** device for room temperature).
+
+### {% linkable_title Configuration %}
+
+To add your Lan2RF gateway into your Home Assistant installation, add one of the following to your `configuration.yaml` file.
+
+```yaml
+# Example configuration.yaml entry, older firmware with no user credentials
+incomfort:
+  host: IP_ADDRESS
+```
+Alternatively, if a **username** & **password** is printed on the back of the gateway:
+
+```yaml
+# Example configuration.yaml entry, newer firmware with user credentials
+incomfort:
+  host: IP_ADDRESS
+  username: USERNAME
+  password: PASSWORD
+```
+
+{% configuration %}
+host:
+  description: The hostname/IP address of the Lan2RF gateway
+  required: true
+  type: string
+username:
+  description: The username of the Lan2RF gateway
+  required: inclusive
+  type: string
+password:
+  description: The password of the Lan2RF gateway
+  required: inclusive
+  type: string
+{% endconfiguration %}